Add a button to exit managed mode.

chrome/browser/managed_mode.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_MANAGED_MODE_H_
 #define CHROME_BROWSER_MANAGED_MODE_H_
 
 #include <set>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
 class Browser;
 template<typename T>
 struct DefaultSingletonTraits;
 class PrefService;
 class Profile;
 
+// Managed mode allows one person to manage the Chrome experience for another
+// person by pre-configuring and then locking a managed User profile.
+// The ManagedMode class provides methods to check whether the browser is in
+// managed mode, and to attempt to enter or leave managed mode.
 class ManagedMode : public BrowserList::Observer,
                     public content::NotificationObserver {
  public:
   typedef base::Callback<void(bool)> EnterCallback;
 
   static void RegisterPrefs(PrefService* prefs);
   static bool IsInManagedMode();
 
   // Calls |callback| with the argument true iff managed mode was entered
   // sucessfully.
@@ skipping 35 matching lines @@
   content::NotificationRegistrar registrar_;
 
   // The managed profile. This is non-NULL only while we're entering
   // managed mode.
   const Profile* managed_profile_;
   std::set<const Browser*> browsers_to_close_;
   std::vector<EnterCallback> callbacks_;
 };
 
 #endif  // CHROME_BROWSER_MANAGED_MODE_H_